Exercise systems that incorporate an anchor and one or more extendible tethers coupled to the anchor to provide exercise resistance have been known for quite some time. For example, U.S. Pat. No. 1,432,013 to Herbert, U.S. Pat. No. 5,362,295 to Nurge and U.S. Patent Application Publication No. 2010/0041528 in the name of Todd disclose arrangements in which elastic cords are attached to a belt so that a user can use the cords to provide exercise resistance to arm movements. However, these arrangements do not gather data about exercise performance.
U.S. Patent Application Publication No. 2014/0142864 in the name of Spears et al. describes an exercise system comprising a belt and two resistive deformable elements connecting the belt to two handles. Although this document does describe collection of exercise data, it proposes a complicated sensor arrangement for achieving this purpose.